I wouldnt be suprised if it is ai shading but called a full ai movie, like they use 3d/2d to fully block out everything, pretty disengenuous to act like thats prompt based ai when it still could require insanely high amounts of effort (you still do the full animation, rigging, etc. just the render/shading part is handled by ai) A lot of ppl do that with simulations, kinda cool actually but I hate how they hype up Ai instead of being genuine about their process, wouldve had 90% of the same result without ai